Sediment removal tub assembly



Sept. 30, 1958 T. R. SMITH '2,854,144

SEDIA/ENT REMOVAL TUB ASSEMBLY Filed Nov. 9, 1954 3 Sheets-Sheet 2 Sept.` 30, 1958 T. R. SMITH SEDIMENT REMOVAL TUB ASSEMBLY 3 Sheets-Sheet 5 Filed NOV. 9, 1954 ms .waant mm mn m5. 7M.. @.AMM m@ .r Mm/m, m4 TM nited States Patent C) i SEDIIWENT REMOVAL TUB ASSEMBLY Thomas R. Smith, Newton, Iowa, assignor to The Maytag Company, Newton, iowa, a corporation of Deiaware Application November 9, 1954, Serial No. 467,727

21 Claims. (Cl. Mii- 382) This invention relates to washing machines for fabrics and more particularly to washing machines utilizing a double tub assembly rotatable on a vertical axis for the centrifugal extraction of fluids from fabrics within the tub. Specifically, this invention relates to an improvement of that type double tub construction to permit sand and heavy sediment separated from the fabrics during the agitation period prior to the centrifugal extraction period to be rapidly removed from within the double tub assembly during the extraction process. In this respect the invention is in furtherance to that shown and described in my prior Patents Nos. 2,637,187, 2,637,- 188 and 2,683,535.

This invention, like those covered in the above patents, constitutes an improvement over the type of double tub construction disclosed in my Patent No. 2,645,108 and assigned to the same asignee as the instant application. In that disclosure so-iled fabrics were placed within an inner basket having a perforate cylindrical sidewall and a perforate bottom wall in spaced relationship to an outer imperforate tub which was fastened to the basket and retained the washing fluid during the agitation and rinse periods. In the spin periods following the agitation and rinse periods, the agitator unit and double tub assembly were spun as an integral unit to extract all liquids through the walls of the perforate basket and over the top of the vertical sidewall of the outer imperforate tub without passing through the fabrics and thereby redepositing the separated sand, dirt and other sediment on the fabrics during the centrifugal extraction process.

This double tub assembly formed from the perforate inner basket nested in spaced relationship with an outer imperforate tub provided a tub assembly having more desirable features than were obtained by the use of the single imperforate tub alone. First, the perforate basketserved as a container for the fabrics while separating the heavier dirt and sediment from the fabrics through its perforate bottom. Furthermore, the basket provided a more rapid and thorough iiuid extraction through its perforate periphery for a given speed than could be accomplished by the use of a single irnperforate tub. Finally, the use of the basket in conjunction with the spaced iiuid retaining outer imperforate tub provided an annular upstanding fluid escape channel between the basket and outer tub so as to prevent recontamination of the fabrics by the centrifugally extracted fluids as they passed from the tub assembly.

However, due to the high speed of rotation necessary to achieve an eiiicient fluid extraction from the fabrics, some sand and sediment separated from the fabrics and deposited between the inner basket and outer tub during the agitation period was not flushed from the outer tub because the vertical component of force of the Water rising up the sidewall of the outer tub was insufficient to overcome the centrifugal force acting on the particles of sand, etc., and resulted in these particles remaining pressed against the sidewall of the outer tub during the ,Y 2,854,144 Patented Sept. 30, 1958 its vertical axis whereby a vertical velocity may be im parted to the particles of sand and heavy sediment within the double tub assembly to overcome the action of the centrifugal force tending to prevent adequate scouring of these particles from within the space between the inner perforate basket and outer imperforate tub forming a part of the doubleV tub assembly.

It is a further object to provide an improved double tubA assembly capable of removing sand and other sediment from the space between the inner basket and imperforate tub during the rst portion of the centrifugal extraction period while eiciently extracting residual uids through the cylindrical wall of the perforate basket during the latter part of the centrifugal extraction process.

It is a further object of this invention to provide an improved double tub assembly which will permit an eiiicient sediment removal from within the double tub assembly at the beginning of the centrifugal extraction period without impairing the efficiency of the uid extraction from the fabrics at higher centrifugal speeds at the latter portion ofthe centrifugal extraction period.

Specifically, it is an object of this invention to provide an improved double tub assembly having an outer imperforate tub and an inner basket spaced apart from the outer tub and provided with vertical groupings of holes in its cylindrical wall together with inverted U-shaped seals around each grouping of holes between the outer tub and inner basket so that a rotation of the double tub assembly on its vertical axis during the uid extraction process produces a pressure head within these seals and within the double tub itself to force water downwardly through the perforate bottom of the basket to ush sand, dirt and heavy sediment from within the bottom sump areas between the tub and basket before forcing the water and sediment to rise over the cylindrical sidewall of the outer tub.

It is still a further object of this invention to provide an improved double tub assembly which is economical as well as efficient in the removal of both fluids and heavy sediment from within the tub during the fluid extraction process.

Other objects and advantages of this invention will be apparent after reference is made to the following speciiication as illustrated in the accompanying drawings, in which:

Figure 1 is a perspective View, partly broken away, showing a double tub assembly (without an agitator unit, supporting gear case or balancing ring) constructed according to the principles of my invention.

Figure 2 is a side elevation of a double tub assembly, partially in section, showing a sump construction and including an agitator unit and driving mechanism for the double tub assembly.

Figure 3 is a view partly broken away to show the bottom wall of the inner tub of the double tub assembly.

Referring now to the drawings there is shown an outer imperforate tub l, an inner basket 11 and an agitator unit 12. Outer imperforate tub 10 is provided with an upwardly directed and slightly outwardly sloping sidewall 13 having an upper terminal edge 14 disposed above the normal liquid level (line A, Figure 2) maintained in the tub for washing operations. Lower wall having an inner terminal portion 16, overlapping ange 17 of gear housing 18, is fastened to ange 17 by means of bolts 19 to form an integral unit with tub ,10... Gasket 20 provides` a` liquid seal between tub`10`and'the'top of'` gear houslng r 18' forming vthe central bottom' portiongo'f'the double tub assemblyi'A Outerrconcentric shaft 23, shown integrally" ly, is securely fastened to they tub 10 by means of bolts 28 carrying` nuts and extending through'cylindrical sidewall 26 and spacer members 29l to maintain the proper spacing between the walls of tub'10 and basket 11.

The. upper portion of basket 11 extends upwardly beyond edge 14 of tub 10 and inwardly towards an access opening generally defined by the rolled edge 36. This construction notV only provides a means for preventing the discharge of fluid and fabrics over portion 35'during the centrifugal extraction operation but also provides a seat for balancing ring 38. Balancing ring 38, of the nature of that described in the above mentioned Patent No. 2,645,108 prevents the wobbling of the double tub assembly at speeds exceeding the critical speed of the tub assembly and forms no part of this invention.

Referring now particularly to the improvement made over the above mentioned Patent No. 2,645,108 it can be seen that in this embodiment ofmy invention cylindrical wall 26 of basket 11 is provided with three vertical groups of holes 41 in the central portion of thatcylindrical wall while bottom wall 27 is provided with an annular band of holes 42 which are reduced in number directly over the recessed sumps 43 formed near the junction of walls 13 and 15 -of tub 10. While the spacing of the side and bottom walls of tub 10 and basket 11 prevents objects of relatively long but restricted lateral measurements such as hairpins, etc. from passing through holes 41 or-42, the spaces within sumps 43 would easily accommodate such articles if holes 42 were continued over the sump areas 43. Consequently, no holes are provided directly over the deepest portions of these recesses though the presence of holes adjacent the shallow portions of sumps 43 aids in'- the ushing of these recesses during the extraction process while not causing undue turbulence in these sumps during the agitation periods. t

In the embodiment shown in the accompanying drawings three sumps 43 are placed 120 apart and are aligned with the alternate imperforate portions 44 of wall 26 as defined by holes 41.

Partially surrounding each of the groupings defined by holes 41V are three two-piece U-shaped seals 46 which are attached to cylindrical wall 26 and are squeezed between tub 10 and basket 11 to partially surround each of these groupings. Though seals 46 may be cemented on basket 11, they are fastened to basket 11 in this embodiment by circular nibs 48 extending from their back faces through basket'll (Figures 2 and 3). Once nibs 48 have been pulled through basket 11, the nib portions extending past walls 26 and 27 are cut off ush with these walls as seals 46 will remain squeezed in place after the assembly of the double tub has been completed. Though seals 46 are contoured to the spacing between tub 10 and basket 11, longitudinal flutes 49 are provided in those surfaces of seals 46 contacting wall 13 to provide a more resilient seal capable of adjusting to variances of that spacing.

ing members for intermediate portions 51 and 52, respectively, and cooperate tok define a bleeder port 55'near the center of each seal. Attached to each of the intermediate members 51 is a downwardly depending leg 56 which extends past the lower limit of holes 41. Depending leg 57, which is attached to the intermediate portion 52, is longer than `leg 56 and extends downwardly between lower wall 15 and bottom wall 27 along the rotational trailing edge of sump 43 before terminating in a junction with gasket Each of the seals 46 has two horizontal intermediate i portions 51 and 52 ush with or slightly below the terminal edge of tub 10 above the upper limit of holes 41; Short depending members 53 and 54 serve as fasten- 32. Both of legs 56 and 57 diverge downwardly towards each other to provide three upwardly converging channels t or passageways 58 formed by legs 57, imperforate portions 44, legs 56 and those portions of wall 13 above sumps 43. This type of seal construction between tub 10 and basket 11 causes most of the water. entering tub 10 from basket 11 to be deflected or forced downwardly around short legs 56 before passing out of the double tub assembly through` channels 58.

In the operationof the double tub assembly described, the assembly is supported in a vertical position on outer concentric shaft 23 to expose the horizontal access opening defined by therolled edge 36 to operator of the unit. l vFabrics are then placed within this opening and the tub t bottom wal-l 15 into the sump areas where it remains dur` ing the remainder of the agitation period.

At the completion of the agitation period, the move-V ment of agitator unit 12 with respect to tub 10 and basket 11 is terminated and the brake restraining the tub 10 from rotation is released permitting tub 10, basket 11 and agitator unit 12 to be spun counterclockwise (Figure 3) as Yan integral unit through outer shaft 23.

The rotating tub assembly develops a uid pressure head within basket 11 proportional to the radius and speed of the rotating assembly which causes the water within basket 11 to flatten against the inner surface of wall 26. The water level immediately surrounding agitator 12 quickly drops causing a surface of the water to form a rough paraboloid as the water rises toward portion 35 of basket 11 during the initial portion of the extraction period. An increasing pressure differential is 1 created between the rising pressure within the spinning basket and the pressure exerted on the water in the upper portion of channel 58 between tub 10 and basket 11. As rthe sole communication between tub 10 and basket 11 is through holes 41 and 42, .the water passing z through holes 41 under this diierential pressure is forced downwardly between the legs 56 and 57 of seals 46 before it rises upwardly through channels 58 and passes over terminal edge 14 of tub V10. Likewise, the pressure within basket 11 causes water to flow downwardly through holes 42 in the bottom of basket 11, along bottom wall 15 and past sumps 43 where it rises upwall 13 and over terminal edge 14.

Due to the counterclockwise rotation of the double tub y. assembly, the water forced from between the legs of seals 46 tends to travel in a clockwise direction relative to legs 56 and 57 before being allowed to travel upward-. ly through channels 58. Legs 57, sealing each of sump pockets 43 fromV each other, prevent the escaping fluids from carrying the flushed Vsediment past legs 57 in a rela-` tive clockwise direction between tub 10.and basket 11 f before passing upwardly from the double tub assembly. Those inside surfaces -of seals 46 `facing and partially surrounding holes 41 serve as detecting surfaces to force A water downwardly towards the bottom ofthe tub assem- Sand and heavier'sediment settling to the bot-- tom wall 27 passes through Vholes 42 and moves along bly for the development of the pressures which canse water to rush downwardly through holes 42 to scour bottom wall 15 and sumps 43, The outside surfaces of legs 57 facing towards imperforate portions 44 not only cooperate with legs 56 to form channels 58, but also limit the rotational travel of the sediment ushed from the bottom of the tub assembly by the water rushing through holes 42. The upwardly decreasing cross sectional areas of converging channels 58 formed by the diverging legs 56 and 57 together with wall portions 44 and wall 13 aid in increasing the velocity of the escaping water as it sweeps the sediment particles upwardly from the bottom areas so that a suicient upwardly directed component of force is produced to overcome the centrifugal forces tending to press these same particles againts the wall 13.

When practically all of the iluids have been extracted from within the double tub assembly, the residual iiuids passing through holes 4i have no iluid pressures forcing them downwardly between the legs 56 and 57. Bleeder ports 55, formed by the short cooperating fastening legs 53 and 54, are therefore provided near the intermediate portion of the U-shaped seals 46. Bleeder ports 55 serve as escape ports to prevent these residual fluids from remaining flattened against wall 13 and trapped within seals 46 at the end of the extraction process. Though large enough to prevent their clogging by lint accumulations, ports 55 have little or no eiect on the maintenance of the pressure differential necessary for adequate sediment removal. It should be noted that while .seals 46 are of a two-piece construction for manufacturing purposes a one-piece seal construction with one or more bleeder holes or notches near Wall 13 in the intermediate portion of the U-shaped one-piece seal would also serve the same function as that of the illustrated embodiment and would not be contrary to the principles of my invention.

It should be noted that the illustratedV embodiment is one of several constructions which may be made in accordance with the teaching of my invention. This invention may be practicedv by using U-shaped seals having no long depending legs extending downwardly between the bottom walls of the outer tub and inner basket. It may also be eciently operated by using a combination of seals having long depending legs cooperating with or without recessed sumps and U-shaped seals having legs of equal length and not extending to the bottom areas of the tub assembly. In addition, a variance of the number of seals used or the degree of peripheral arcs covered by the seals is not contrary to the principles of my invention.

Thus it can be seen that l have provided a simple and economical double tub assembly capable of ilushing separated sediment from within the assembly while retaining the advantages of a perforate centrifugal fluid extractor. The construction disclosed is dependent solely upon the radius and rotational speed of the assembly and an adequate supply of water within the basket to insure a high pressure head and is therefore operative during all spin cycles without requiring further control or attention by the operator of the unit embodying this double tub assembly.

I claim:

1. A rotatable tub assembly comprising, an inner tub member including a sidewall having a plurality of spaced groupings of foramina, an outer tub member spaced from said inner tub member, and resilient sealing members having depending legs positioned between said tub members and partially surrounding each of said respective groupings and to form a plurality of upwardly directed channels between said tub members.

2. A rotatable tub assembly comprising, an inner tub member including a sidewall having a plurality of spaced groupings of foramina, an outer tub member spaced from said inner tub member, and resilient sealing members having diverging depending legs-positioned between said tub members and partially surroundingeach of said` groupings and to form a plurality of upwardly converging channels between said tub members.

3. A rotatable tub assembly comprising, an inner tub member including a sidewall having a plurality of spaced groupings of oramina, an outer tub member spaced from said inner tub member, sediment pockets in said outer tub member, and resilent sealing members wedged between said tub members and having depending legs partially surrounding each of said groups and to form between said tub members a plurality of upwardly directed channels communicating with said sediment pockets.

4. Ay rotatable tub assembly comprising, an inner tub members including a sidewall having a plurality of spaced groupings of foramina, an outer tub member spaced from said inner tub member, a plurality of sediment pockets between said tub members, resilient sealing members partially surrounding each of said groupings to form.

between said tub members upwardly directed channels communicating with said sediment pockets, said sealing members including depending legs sealing each of said sediment pockets from each other.

5. A rotatable double-walled tub assembly adapted to contain iluid comprising, an inner wall having a plurality of spaced foraminous sectors separated from each other by imperforate sectors, an imperforate outer wall spaced from said inner wall, means positioned between said walls and cooperating therewith to dene effluent passageways between said foraminous sectors, said means partially encompassing said foraminous sectors to preclude the admission of duid from within said tub assembly to said passageways except adjacent the bottom` of the latter.

6. A rotatable tub assembly adapted to contain iluid comprising, an inner wall having a plurality of spaced foraminous sectors separated from each other by imperforate sectors, an imperforate outer wall spaced from said inner Wall, means positioned between said walls and cooperating therewith to dene upstanding efuent passageways of converging cross section between said foraminous sectors, said means partially encompassing said foraminous sectors to preclude uid passing through said'foraminous sectors from entering said passageways except adjacent the bottom of the latter.

7. A double-walled tub assembly adapted to contain fluid and to be rotated about a vertical axis comprising, an inner wall having a plurality of spaced foraminous sectors separated from each other by imperforate sectors, an outer imperforate wall spaced from said inner wall, partition members having depending legs positioned between said walls and cooperating therewith to define upstanding efuent passageways between said foraminous sectors, said partition members encompassing the upper extremities of said foraminous sectors to preclude iluid passing through said foraminous sectors from entering said passageways except adjacent the lower ends of said legs.

8. The invention of claim 7 in which each of said partition members is provided with a bleeder port intermediate its respective legs.

9. The invention of claim 7 in which each of said partition members is a two-sectional resilient member wedged between said inner and outer walls.

10. The invention of claim 7 in which each of said partition members has two legs of unequal length, the longer of said legs providing a seal between each of said foraminous sectors to channel uid passing through said foraminous sectors into the upstanding passageway immediatley adjacent the shorter leg of each respective partition member.

11. The invention of claim 10 in which each of said longer legs of said partition member denes the leading edge of said respective partition members during rotation of said tub.

. 12. The invention'of claim 10 in which each ofsaid partition members Ais provided with a bleeder port` intermediate said depending legs.

13. A double-walled tub assembly adapted to receive uid and to be rotated about a vertical axis to centrifugally extract uid retained therein comprising, an imperforate container, an inner basket nested within said container, said basket having a cylindrical wall spaced from saidcontainer and provided with a plurality of foraminous sectors separated from each other by imperforate sectors, a perforate bottom wall in said basket joining said cylindrical wall and spaced from said container, means positioned between said container and said basket and cooperating therewithv to define upstanding eiuent passageways between said foraminous sectors, said means partially encompassing said foraminous sectors to preclude the admission of uid from said tub assembly to said passageways except adjacent-the bottom of the latter. n

14. The invention of claim 13 in which said container is-provided with sump pockets adjacent the lower ends of said passageways.

15. A double-walled tub assembly adapted to receive fluid and to be rotated about a vertical axis to'centrifugally' extract uid retained therein comprising, an imperforate container, an inner basket nested within said container, said basket having a cylindrical wallV spaced from said container and provided with a plurality of foraminous sectors separatedfrom each other by imperforate sectors, a perforate bottom wall in said basket joining said cylindrical wall and spaced from said container, partition members positioned between said container and Asaid 'basket and cooperating therewithY to define effluent passageways between said foraminous sectors, sump pockets in said container for collecting sediment particles passing through said perforate bottom wall, said sump pockets being positioned beneath 1 said passageways to be flushed free of sedimentparticles' by uid flow through said passageways during rotation of said tub assembly.

16. The invention of claim 15 in which each of `said partition members hasa pair of depending legs of unequal length with the longer leg of each partition member ccmstituting the leading edge of its respective partition member during rotation of said tub assembly.

17. The invention of claim 16 in which the longer leg I 8 of each partition member each other.

18. The invention of claim 16 inV which the shorter leg of each of said partition members constitutes the trailing edge ofits respective partition member pastY which uid ows into an adjacent passageway during rotation of said tub assembly.

19. The invention-of claim 15 iniwhich said bottomly wall is imperforate immediately over each of said sump pockets.

20. A revoluble double walled tub assembly adapted to contain uid comprising, an endless inner wall including a foraminous sector and an imperforate sector, an endless outer wall spaced from and encompassing said inner wall, means positioned between said` walls and` partially encompassing said foraminous sectorjto form with said walls an euent channel adjacent said imperforate sector for the discharge of uid from said tub assembly, and means for rotating said walls to develop a pressure head for forcing fluid contained within said tub assembly through said foraminous sector and out said efuent channel to ush the space between saidwalls.

21. A revoluble double Walled tub assembly adapted Y to contain uid comprising, an upstanding endless inner Wall including a foraminous sector and an imperforate sector, an upstanding endless outer wall spaced from and encompassing said inner wall, partition members positioned between said walls and encompassing the upper extremities of said foraminous sector, said partition members including dependent portions cooperating with said walls to define upstanding euent channels adjacent said imperforate sector for the discharge of fluid from said tub assembly, and means for rotating said walls to f force uid through said foraminous sector and out of said upstanding channel to ilush the space between said walls.

References Cited in the le of this patent UNITED STATES PATENTS seals each sump A' pocket from- UNTTTD STATES TATTNT @TTTCT @EMHCMFE @F QCRREHN Patent Non 2,85491412, September 3G, 1958 Thomas Ro Smun It is herebT certified 'that error appeazs in Jshe prin-bed specification of the above numbered patent requiring correction and 'that the said Letters Patent should read as corrected below,x

Column l, line 3l, for "assignee" ree; m aesgneo wg column 5, line '7Gg and column oj line 3g strike out "endg ooourrenoe; column line 9, for "reslent" read m resilient m; line llp for "groups and" reed me groupings ttest:

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